One thing that's exciting about the application of evolutionary biology methods to linguistics is that we can sharpen our understanding of just how the language has changed through time--and will continue changing tomorrow. This recent piece from England describes how some of the Oldest English words have been identified, thanks to the use of computational analysis of ancient texts, and this group from Harvard made a splash in '07 by coming up with a way to predict the future of past-tense verbs. That is, the past tense of go and have won't become goed and haved anytime soon, whereas the past tense of wed will likely become regularized (wedded) sooner rather than later.

If descriptivist takes on language clash with your sense of certainty about what is and isn't correct English, I recommend a visit to a website like Worldometers.info. It's an effective reminder of one's small and temporary place in the world. In a global society that's changing this fast, notions of a language locked in time and form seem especially quaint, if not absurd.